Effect of dietary iron supplementation on the course of Plasmodium chabaudi malaria in weanling mice

The hypothesis that iron repletion may enhance parasite multiplication and aggravate malaria infection in iron-deficient hosts was tested in a murine model of dietary iron deficiency and iron supplementation. Weanling C57Bl/6 J mice were fed diets containing either 15mg iron/kg diet (Group D, n=20) o r 50 mg iron/kg diet (Group N, n=12). After 30 days, when hemoglobin levels (Hb in g/100ml; Mean +/- SD) were significantly lower in Group D (13.7 +/- 1.2) than in from Group N (15.4 +/- 2.0), 16 mice from Group D and 8 mice from Group N were inoculated intraperitoneally with 10(4) intraerythrocytic Plasmodium chabaudi (AS strain) malaria parasites. Four animals from each group remained as non-infected controls. At the time of inoculation, 8 mice from Group D (thereafter Group DS) and all animals from Group N (thereafte r Group NS) were transferred to a diet containing 140 mg iron/kg, whereas 8 mice from Group D were maintained on the original iron-deficient diet. At the peak of parasitemias (day 10-11 post-infection), anemia was less severe in mice from Group DS if compared to those from Group D (Hb: 4.5 +/- 1.1 v s. 3.4 +/- 1.0), but more severe than in those from Group NS (5.6 +/- 1.8). However, the time course of parasitemias was similar in all groups. Mortal ity was higher among mice from Groups D and DS (87.5%) than in those from G roup NS (37.5%; Fisher's exact test, p = 0.0104). These data indicate that neither iron deficiency suppressed nor iron repletion enhanced P. chabaudi multiplication in weanling mice. Moreover, dietary iron supplementation ind uced hemoglobin response in iron-deficient mice but did not increase their ability to resist severe malarial anemia. (C) 2000 Elsevier Sciance Inc.